Various methods and apparatus exist to strengthen leg muscles, especially the muscles of the calf. Generally these devices have a common feature, namely the raising of the heels from a flat surface. The exercise can be done while carrying a barbell or other free weights, or it can be carried out by lifting some weighted apparatus while lifting the heels from a standing position. The lifting of the heels to a position standing on the balls and toes of the feet necessarily creates a tendency to instability, especially if free weights are being carried and additional balance challenges are thereby presented. A safe and effective apparatus to allow the exercise of the calf muscles in a stable position would be a salutary development.